2 * Network Block Device - server
4 * Copyright 1996-1998 Pavel Machek, distribute under GPL
5 * <pavel@atrey.karlin.mff.cuni.cz>
6 * Copyright 2001-2004 Wouter Verhelst <wouter@debian.org>
7 * Copyright 2002 Anton Altaparmakov <aia21@cam.ac.uk>
9 * Version 1.0 - hopefully 64-bit-clean
10 * Version 1.1 - merging enhancements from Josh Parsons, <josh@coombs.anu.edu.au>
11 * Version 1.2 - autodetect size of block devices, thanx to Peter T. Breuer" <ptb@it.uc3m.es>
12 * Version 1.5 - can compile on Unix systems that don't have 64 bit integer
13 * type, or don't have 64 bit file offsets by defining FS_32BIT
14 * in compile options for nbd-server *only*. This can be done
15 * with make FSCHOICE=-DFS_32BIT nbd-server. (I don't have the
16 * original autoconf input file, or I would make it a configure
17 * option.) Ken Yap <ken@nlc.net.au>.
18 * Version 1.6 - fix autodetection of block device size and really make 64 bit
19 * clean on 32 bit machines. Anton Altaparmakov <aia21@cam.ac.uk>
20 * Version 2.0 - Version synchronised with client
21 * Version 2.1 - Reap zombie client processes when they exit. Removed
22 * (uncommented) the _IO magic, it's no longer necessary. Wouter
23 * Verhelst <wouter@debian.org>
24 * Version 2.2 - Auto switch to read-only mode (usefull for floppies).
25 * Version 2.3 - Fixed code so that Large File Support works. This
26 * removes the FS_32BIT compile-time directive; define
27 * _FILE_OFFSET_BITS=64 and _LARGEFILE_SOURCE if you used to be
28 * using FS_32BIT. This will allow you to use files >2GB instead of
29 * having to use the -m option. Wouter Verhelst <wouter@debian.org>
30 * Version 2.4 - Added code to keep track of children, so that we can
31 * properly kill them from initscripts. Add a call to daemon(),
32 * so that processes don't think they have to wait for us, which is
33 * interesting for initscripts as well. Wouter Verhelst
35 * Version 2.5 - Bugfix release: forgot to reset child_arraysize to
36 * zero after fork()ing, resulting in nbd-server going berserk
37 * when it receives a signal with at least one child open. Wouter
38 * Verhelst <wouter@debian.org>
39 * 10/10/2003 - Added socket option SO_KEEPALIVE (sf.net bug 819235);
40 * rectified type of mainloop::size_host (sf.net bugs 814435 and
41 * 817385); close the PID file after writing to it, so that the
42 * daemon can actually be found. Wouter Verhelst
44 * 10/10/2003 - Size of the data "size_host" was wrong and so was not
45 * correctly put in network endianness. Many types were corrected
46 * (size_t and off_t instead of int). <vspaceg@sourceforge.net>
47 * Version 2.6 - Some code cleanup.
48 * Version 2.7 - Better build system.
49 * 11/02/2004 - Doxygenified the source, modularized it a bit. Needs a
50 * lot more work, but this is a start. Wouter Verhelst
52 * 16/03/2010 - Add IPv6 support.
53 * Kitt Tientanopajai <kitt@kitty.in.th>
54 * Neutron Soutmun <neo.neutron@gmail.com>
55 * Suriya Soutmun <darksolar@gmail.com>
58 /* Includes LFS defines, which defines behaviours of some of the following
59 * headers, so must come before those */
62 #include <sys/types.h>
63 #include <sys/socket.h>
65 #include <sys/select.h> /* select */
66 #include <sys/wait.h> /* wait */
67 #ifdef HAVE_SYS_IOCTL_H
68 #include <sys/ioctl.h>
70 #include <sys/param.h>
71 #ifdef HAVE_SYS_MOUNT_H
72 #include <sys/mount.h> /* For BLKGETSIZE */
74 #include <signal.h> /* sigaction */
76 #include <netinet/tcp.h>
77 #include <netinet/in.h>
85 #include <arpa/inet.h>
95 /* used in cliserv.h, so must come first */
96 #define MY_NAME "nbd_server"
100 #include <sdp_inet.h>
103 /** Default position of the config file */
105 #define SYSCONFDIR "/etc"
107 #define CFILE SYSCONFDIR "/nbd-server/config"
109 /** Where our config file actually is */
110 gchar* config_file_pos;
112 /** What user we're running as */
114 /** What group we're running as */
115 gchar* rungroup=NULL;
116 /** whether to export using the old negotiation protocol (port-based) */
117 gboolean do_oldstyle=FALSE;
119 /* Whether we should avoid forking */
122 /** Logging macros, now nothing goes to syslog unless you say ISSERVER */
124 #define msg2(a,b) syslog(a,b)
125 #define msg3(a,b,c) syslog(a,b,c)
126 #define msg4(a,b,c,d) syslog(a,b,c,d)
128 #define msg2(a,b) g_message(b)
129 #define msg3(a,b,c) g_message(b,c)
130 #define msg4(a,b,c,d) g_message(b,c,d)
133 /* Debugging macros */
136 #define DEBUG(...) printf(__VA_ARGS__)
140 #ifndef PACKAGE_VERSION
141 #define PACKAGE_VERSION ""
144 * The highest value a variable of type off_t can reach. This is a signed
145 * integer, so set all bits except for the leftmost one.
147 #define OFFT_MAX ~((off_t)1<<(sizeof(off_t)*8-1))
148 #define LINELEN 256 /**< Size of static buffer used to read the
149 authorization file (yuck) */
150 #define BUFSIZE ((1024*1024)+sizeof(struct nbd_reply)) /**< Size of buffer that can hold requests */
151 #define DIFFPAGESIZE 4096 /**< diff file uses those chunks */
152 #define F_READONLY 1 /**< flag to tell us a file is readonly */
153 #define F_MULTIFILE 2 /**< flag to tell us a file is exported using -m */
154 #define F_COPYONWRITE 4 /**< flag to tell us a file is exported using
156 #define F_AUTOREADONLY 8 /**< flag to tell us a file is set to autoreadonly */
157 #define F_SPARSE 16 /**< flag to tell us copyronwrite should use a sparse file */
158 #define F_SDP 32 /**< flag to tell us the export should be done using the Socket Direct Protocol for RDMA */
159 #define F_SYNC 64 /**< Whether to fsync() after a write */
160 #define F_FLUSH 128 /**< Whether server wants FLUSH to be sent by the client */
161 #define F_FUA 256 /**< Whether server wants FUA to be sent by the client */
162 #define F_ROTATIONAL 512 /**< Whether server wants the client to implement the elevator algorithm */
163 GHashTable *children;
164 char pidfname[256]; /**< name of our PID file */
165 char pidftemplate[256]; /**< template to be used for the filename of the PID file */
166 char default_authname[] = SYSCONFDIR "/nbd-server/allow"; /**< default name of allow file */
168 #define NEG_INIT (1 << 0)
169 #define NEG_OLD (1 << 1)
170 #define NEG_MODERN (1 << 2)
172 int modernsock=0; /**< Socket for the modern handler. Not used
173 if a client was only specified on the
174 command line; only port used if
175 oldstyle is set to false (and then the
176 command-line client isn't used, gna gna) */
177 char* modern_listen; /**< listenaddr value for modernsock */
178 char* modernport=NBD_DEFAULT_PORT; /**< Port number on which to listen for
179 new-style nbd-client connections */
182 * Types of virtuatlization
185 VIRT_NONE=0, /**< No virtualization */
186 VIRT_IPLIT, /**< Literal IP address as part of the filename */
187 VIRT_IPHASH, /**< Replacing all dots in an ip address by a / before
188 doing the same as in IPLIT */
189 VIRT_CIDR, /**< Every subnet in its own directory */
193 * Variables associated with a server.
196 gchar* exportname; /**< (unprocessed) filename of the file we're exporting */
197 off_t expected_size; /**< size of the exported file as it was told to
198 us through configuration */
199 gchar* listenaddr; /**< The IP address we're listening on */
200 unsigned int port; /**< port we're exporting this file at */
201 char* authname; /**< filename of the authorization file */
202 int flags; /**< flags associated with this exported file */
203 int socket; /**< The socket of this server. */
204 int socket_family; /**< family of the socket */
205 VIRT_STYLE virtstyle;/**< The style of virtualization, if any */
206 uint8_t cidrlen; /**< The length of the mask when we use
207 CIDR-style virtualization */
208 gchar* prerun; /**< command to be ran after connecting a client,
209 but before starting to serve */
210 gchar* postrun; /**< command that will be ran after the client
212 gchar* servename; /**< name of the export as selected by nbd-client */
213 int max_connections; /**< maximum number of opened connections */
214 gchar* transactionlog;/**< filename for transaction log */
218 * Variables associated with a client socket.
221 int fhandle; /**< file descriptor */
222 off_t startoff; /**< starting offset of this file */
226 off_t exportsize; /**< size of the file we're exporting */
227 char *clientname; /**< peer */
228 char *exportname; /**< (processed) filename of the file we're exporting */
229 GArray *export; /**< array of FILE_INFO of exported files;
230 array size is always 1 unless we're
231 doing the multiple file option */
232 int net; /**< The actual client socket */
233 SERVER *server; /**< The server this client is getting data from */
234 char* difffilename; /**< filename of the copy-on-write file, if any */
235 int difffile; /**< filedescriptor of copyonwrite file. @todo
236 shouldn't this be an array too? (cfr export) Or
237 make -m and -c mutually exclusive */
238 u32 difffilelen; /**< number of pages in difffile */
239 u32 *difmap; /**< see comment on the global difmap for this one */
240 gboolean modern; /**< client was negotiated using modern negotiation protocol */
241 int transactionlogfd;/**< fd for transaction log */
245 * Type of configuration file values
248 PARAM_INT, /**< This parameter is an integer */
249 PARAM_STRING, /**< This parameter is a string */
250 PARAM_BOOL, /**< This parameter is a boolean */
254 * Configuration file values
257 gchar *paramname; /**< Name of the parameter, as it appears in
259 gboolean required; /**< Whether this is a required (as opposed to
260 optional) parameter */
261 PARAM_TYPE ptype; /**< Type of the parameter. */
262 gpointer target; /**< Pointer to where the data of this
263 parameter should be written. If ptype is
264 PARAM_BOOL, the data is or'ed rather than
266 gint flagval; /**< Flag mask for this parameter in case ptype
271 * Translate a command name into human readable form
273 * @param command The command number (after applying NBD_CMD_MASK_COMMAND)
274 * @return pointer to the command name
276 static inline const char * getcommandname(uint64_t command) {
279 return "NBD_CMD_READ";
281 return "NBD_CMD_WRITE";
283 return "NBD_CMD_DISC";
285 return "NBD_CMD_FLUSH";
293 * Check whether a client is allowed to connect. Works with an authorization
294 * file which contains one line per machine, no wildcards.
296 * @param opts The client who's trying to connect.
297 * @return 0 - authorization refused, 1 - OK
299 int authorized_client(CLIENT *opts) {
300 const char *ERRMSG="Invalid entry '%s' in authfile '%s', so, refusing all connections.";
305 struct in_addr client;
306 struct in_addr cltemp;
309 if ((f=fopen(opts->server->authname,"r"))==NULL) {
310 msg4(LOG_INFO,"Can't open authorization file %s (%s).",
311 opts->server->authname,strerror(errno)) ;
315 inet_aton(opts->clientname, &client);
316 while (fgets(line,LINELEN,f)!=NULL) {
317 if((tmp=index(line, '/'))) {
318 if(strlen(line)<=tmp-line) {
319 msg4(LOG_CRIT, ERRMSG, line, opts->server->authname);
323 if(!inet_aton(line,&addr)) {
324 msg4(LOG_CRIT, ERRMSG, line, opts->server->authname);
327 len=strtol(tmp, NULL, 0);
328 addr.s_addr>>=32-len;
329 addr.s_addr<<=32-len;
330 memcpy(&cltemp,&client,sizeof(client));
331 cltemp.s_addr>>=32-len;
332 cltemp.s_addr<<=32-len;
333 if(addr.s_addr == cltemp.s_addr) {
337 if (strncmp(line,opts->clientname,strlen(opts->clientname))==0) {
347 * Read data from a file descriptor into a buffer
349 * @param f a file descriptor
350 * @param buf a buffer
351 * @param len the number of bytes to be read
353 static inline void readit(int f, void *buf, size_t len) {
357 if ((res = read(f, buf, len)) <= 0) {
358 if(errno != EAGAIN) {
359 err("Read failed: %m");
369 * Consume data from an FD that we don't want
371 * @param f a file descriptor
372 * @param buf a buffer
373 * @param len the number of bytes to consume
374 * @param bufsiz the size of the buffer
376 static inline void consume(int f, void * buf, size_t len, size_t bufsiz) {
379 curlen = (len>bufsiz)?bufsiz:len;
380 readit(f, buf, curlen);
387 * Write data from a buffer into a filedescriptor
389 * @param f a file descriptor
390 * @param buf a buffer containing data
391 * @param len the number of bytes to be written
393 static inline void writeit(int f, void *buf, size_t len) {
397 if ((res = write(f, buf, len)) <= 0)
398 err("Send failed: %m");
405 * Print out a message about how to use nbd-server. Split out to a separate
406 * function so that we can call it from multiple places
409 printf("This is nbd-server version " VERSION "\n");
410 printf("Usage: [ip:|ip6@]port file_to_export [size][kKmM] [-l authorize_file] [-r] [-m] [-c] [-C configuration file] [-p PID file name] [-o section name] [-M max connections]\n"
411 "\t-r|--read-only\t\tread only\n"
412 "\t-m|--multi-file\t\tmultiple file\n"
413 "\t-c|--copy-on-write\tcopy on write\n"
414 "\t-C|--config-file\tspecify an alternate configuration file\n"
415 "\t-l|--authorize-file\tfile with list of hosts that are allowed to\n\t\t\t\tconnect.\n"
416 "\t-p|--pid-file\t\tspecify a filename to write our PID to\n"
417 "\t-o|--output-config\toutput a config file section for what you\n\t\t\t\tspecified on the command line, with the\n\t\t\t\tspecified section name\n"
418 "\t-M|--max-connections\tspecify the maximum number of opened connections\n\n"
419 "\tif port is set to 0, stdin is used (for running from inetd).\n"
420 "\tif file_to_export contains '%%s', it is substituted with the IP\n"
421 "\t\taddress of the machine trying to connect\n"
422 "\tif ip is set, it contains the local IP address on which we're listening.\n\tif not, the server will listen on all local IP addresses\n");
423 printf("Using configuration file %s\n", CFILE);
426 /* Dumps a config file section of the given SERVER*, and exits. */
427 void dump_section(SERVER* serve, gchar* section_header) {
428 printf("[%s]\n", section_header);
429 printf("\texportname = %s\n", serve->exportname);
430 printf("\tlistenaddr = %s\n", serve->listenaddr);
431 printf("\tport = %d\n", serve->port);
432 if(serve->flags & F_READONLY) {
433 printf("\treadonly = true\n");
435 if(serve->flags & F_MULTIFILE) {
436 printf("\tmultifile = true\n");
438 if(serve->flags & F_COPYONWRITE) {
439 printf("\tcopyonwrite = true\n");
441 if(serve->expected_size) {
442 printf("\tfilesize = %lld\n", (long long int)serve->expected_size);
444 if(serve->authname) {
445 printf("\tauthfile = %s\n", serve->authname);
451 * Parse the command line.
453 * @param argc the argc argument to main()
454 * @param argv the argv argument to main()
456 SERVER* cmdline(int argc, char *argv[]) {
460 struct option long_options[] = {
461 {"read-only", no_argument, NULL, 'r'},
462 {"multi-file", no_argument, NULL, 'm'},
463 {"copy-on-write", no_argument, NULL, 'c'},
464 {"dont-fork", no_argument, NULL, 'd'},
465 {"authorize-file", required_argument, NULL, 'l'},
466 {"config-file", required_argument, NULL, 'C'},
467 {"pid-file", required_argument, NULL, 'p'},
468 {"output-config", required_argument, NULL, 'o'},
469 {"max-connection", required_argument, NULL, 'M'},
476 gboolean do_output=FALSE;
477 gchar* section_header="";
483 serve=g_new0(SERVER, 1);
484 serve->authname = g_strdup(default_authname);
485 serve->virtstyle=VIRT_IPLIT;
486 while((c=getopt_long(argc, argv, "-C:cdl:mo:rp:M:", long_options, &i))>=0) {
489 /* non-option argument */
490 switch(nonspecial++) {
492 if(strchr(optarg, ':') == strrchr(optarg, ':')) {
493 addr_port=g_strsplit(optarg, ":", 2);
495 /* Check for "@" - maybe user using this separator
498 g_strfreev(addr_port);
499 addr_port=g_strsplit(optarg, "@", 2);
502 addr_port=g_strsplit(optarg, "@", 2);
506 serve->port=strtol(addr_port[1], NULL, 0);
507 serve->listenaddr=g_strdup(addr_port[0]);
509 serve->listenaddr=NULL;
510 serve->port=strtol(addr_port[0], NULL, 0);
512 g_strfreev(addr_port);
515 serve->exportname = g_strdup(optarg);
516 if(serve->exportname[0] != '/') {
517 fprintf(stderr, "E: The to be exported file needs to be an absolute filename!\n");
522 last=strlen(optarg)-1;
524 if (suffix == 'k' || suffix == 'K' ||
525 suffix == 'm' || suffix == 'M')
527 es = (off_t)atoll(optarg);
535 serve->expected_size = es;
540 serve->flags |= F_READONLY;
543 serve->flags |= F_MULTIFILE;
547 section_header = g_strdup(optarg);
550 strncpy(pidftemplate, optarg, 256);
553 serve->flags |=F_COPYONWRITE;
559 g_free(config_file_pos);
560 config_file_pos=g_strdup(optarg);
563 g_free(serve->authname);
564 serve->authname=g_strdup(optarg);
567 serve->max_connections = strtol(optarg, NULL, 0);
575 /* What's left: the port to export, the name of the to be exported
576 * file, and, optionally, the size of the file, in that order. */
585 g_critical("Need a complete configuration on the command line to output a config file section!");
588 dump_section(serve, section_header);
594 * Error codes for config file parsing
597 CFILE_NOTFOUND, /**< The configuration file is not found */
598 CFILE_MISSING_GENERIC, /**< The (required) group "generic" is missing */
599 CFILE_KEY_MISSING, /**< A (required) key is missing */
600 CFILE_VALUE_INVALID, /**< A value is syntactically invalid */
601 CFILE_VALUE_UNSUPPORTED,/**< A value is not supported in this build */
602 CFILE_PROGERR, /**< Programmer error */
603 CFILE_NO_EXPORTS, /**< A config file was specified that does not
604 define any exports */
605 CFILE_INCORRECT_PORT, /**< The reserved port was specified for an
610 * Remove a SERVER from memory. Used from the hash table
612 void remove_server(gpointer s) {
616 g_free(server->exportname);
618 g_free(server->authname);
619 if(server->listenaddr)
620 g_free(server->listenaddr);
622 g_free(server->prerun);
624 g_free(server->postrun);
625 if(server->transactionlog)
626 g_free(server->transactionlog);
632 * @param s the old server we want to duplicate
633 * @return new duplicated server
635 SERVER* dup_serve(SERVER *s) {
636 SERVER *serve = NULL;
638 serve=g_new0(SERVER, 1);
643 serve->exportname = g_strdup(s->exportname);
645 serve->expected_size = s->expected_size;
648 serve->listenaddr = g_strdup(s->listenaddr);
650 serve->port = s->port;
653 serve->authname = strdup(s->authname);
655 serve->flags = s->flags;
656 serve->socket = s->socket;
657 serve->socket_family = s->socket_family;
658 serve->virtstyle = s->virtstyle;
659 serve->cidrlen = s->cidrlen;
662 serve->prerun = g_strdup(s->prerun);
665 serve->postrun = g_strdup(s->postrun);
667 if(s->transactionlog)
668 serve->transactionlog = g_strdup(s->transactionlog);
671 serve->servename = g_strdup(s->servename);
673 serve->max_connections = s->max_connections;
679 * append new server to array
681 * @param a server array
682 * @return 0 success, -1 error
684 int append_serve(SERVER *s, GArray *a) {
686 struct addrinfo hints;
687 struct addrinfo *ai = NULL;
688 struct addrinfo *rp = NULL;
689 char host[NI_MAXHOST];
695 err("Invalid parsing server");
699 port = g_strdup_printf("%d", s->port);
701 memset(&hints,'\0',sizeof(hints));
702 hints.ai_family = AF_UNSPEC;
703 hints.ai_socktype = SOCK_STREAM;
704 hints.ai_flags = AI_ADDRCONFIG | AI_PASSIVE;
705 hints.ai_protocol = IPPROTO_TCP;
707 e = getaddrinfo(s->listenaddr, port, &hints, &ai);
713 for (rp = ai; rp != NULL; rp = rp->ai_next) {
714 e = getnameinfo(rp->ai_addr, rp->ai_addrlen, host, sizeof(host), NULL, 0, NI_NUMERICHOST);
716 if (e != 0) { // error
717 fprintf(stderr, "getnameinfo: %s\n", gai_strerror(e));
721 // duplicate server and set listenaddr to resolved IP address
724 ns->listenaddr = g_strdup(host);
725 ns->socket_family = rp->ai_family;
726 g_array_append_val(a, *ns);
734 fprintf(stderr, "getaddrinfo failed on listen host/address: %s (%s)\n", s->listenaddr ? s->listenaddr : "any", gai_strerror(e));
745 * Parse the config file.
747 * @param f the name of the config file
748 * @param e a GError. @see CFILE_ERRORS for what error values this function can
750 * @return a Array of SERVER* pointers, If the config file is empty or does not
751 * exist, returns an empty GHashTable; if the config file contains an
752 * error, returns NULL, and e is set appropriately
754 GArray* parse_cfile(gchar* f, GError** e) {
755 const char* DEFAULT_ERROR = "Could not parse %s in group %s: %s";
756 const char* MISSING_REQUIRED_ERROR = "Could not find required value %s in group %s: %s";
758 gchar *virtstyle=NULL;
760 { "exportname", TRUE, PARAM_STRING, &(s.exportname), 0 },
761 { "port", TRUE, PARAM_INT, &(s.port), 0 },
762 { "authfile", FALSE, PARAM_STRING, &(s.authname), 0 },
763 { "filesize", FALSE, PARAM_INT, &(s.expected_size), 0 },
764 { "virtstyle", FALSE, PARAM_STRING, &(virtstyle), 0 },
765 { "prerun", FALSE, PARAM_STRING, &(s.prerun), 0 },
766 { "postrun", FALSE, PARAM_STRING, &(s.postrun), 0 },
767 { "transactionlog", FALSE, PARAM_STRING, &(s.transactionlog), 0 },
768 { "readonly", FALSE, PARAM_BOOL, &(s.flags), F_READONLY },
769 { "multifile", FALSE, PARAM_BOOL, &(s.flags), F_MULTIFILE },
770 { "copyonwrite", FALSE, PARAM_BOOL, &(s.flags), F_COPYONWRITE },
771 { "sparse_cow", FALSE, PARAM_BOOL, &(s.flags), F_SPARSE },
772 { "sdp", FALSE, PARAM_BOOL, &(s.flags), F_SDP },
773 { "sync", FALSE, PARAM_BOOL, &(s.flags), F_SYNC },
774 { "flush", FALSE, PARAM_BOOL, &(s.flags), F_FLUSH },
775 { "fua", FALSE, PARAM_BOOL, &(s.flags), F_FUA },
776 { "rotational", FALSE, PARAM_BOOL, &(s.flags), F_ROTATIONAL },
777 { "listenaddr", FALSE, PARAM_STRING, &(s.listenaddr), 0 },
778 { "maxconnections", FALSE, PARAM_INT, &(s.max_connections), 0 },
780 const int lp_size=sizeof(lp)/sizeof(PARAM);
782 { "user", FALSE, PARAM_STRING, &runuser, 0 },
783 { "group", FALSE, PARAM_STRING, &rungroup, 0 },
784 { "oldstyle", FALSE, PARAM_BOOL, &do_oldstyle, 1 },
785 { "listenaddr", FALSE, PARAM_STRING, &modern_listen, 0 },
786 { "port", FALSE, PARAM_STRING, &modernport, 0 },
789 int p_size=sizeof(gp)/sizeof(PARAM);
792 const char *err_msg=NULL;
803 errdomain = g_quark_from_string("parse_cfile");
804 cfile = g_key_file_new();
805 retval = g_array_new(FALSE, TRUE, sizeof(SERVER));
806 if(!g_key_file_load_from_file(cfile, f, G_KEY_FILE_KEEP_COMMENTS |
807 G_KEY_FILE_KEEP_TRANSLATIONS, &err)) {
808 g_set_error(e, errdomain, CFILE_NOTFOUND, "Could not open config file %s.", f);
809 g_key_file_free(cfile);
812 startgroup = g_key_file_get_start_group(cfile);
813 if(!startgroup || strcmp(startgroup, "generic")) {
814 g_set_error(e, errdomain, CFILE_MISSING_GENERIC, "Config file does not contain the [generic] group!");
815 g_key_file_free(cfile);
818 groups = g_key_file_get_groups(cfile, NULL);
819 for(i=0;groups[i];i++) {
820 memset(&s, '\0', sizeof(SERVER));
822 /* After the [generic] group, start parsing exports */
827 for(j=0;j<p_size;j++) {
828 g_assert(p[j].target != NULL);
829 g_assert(p[j].ptype==PARAM_INT||p[j].ptype==PARAM_STRING||p[j].ptype==PARAM_BOOL);
832 ival = g_key_file_get_integer(cfile,
837 *((gint*)p[j].target) = ival;
841 sval = g_key_file_get_string(cfile,
846 *((gchar**)p[j].target) = sval;
850 bval = g_key_file_get_boolean(cfile,
852 p[j].paramname, &err);
855 *((gint*)p[j].target) |= p[j].flagval;
857 *((gint*)p[j].target) &= ~(p[j].flagval);
863 if(err->code == G_KEY_FILE_ERROR_KEY_NOT_FOUND) {
865 /* Ignore not-found error for optional values */
869 err_msg = MISSING_REQUIRED_ERROR;
872 err_msg = DEFAULT_ERROR;
874 g_set_error(e, errdomain, CFILE_VALUE_INVALID, err_msg, p[j].paramname, groups[i], err->message);
875 g_array_free(retval, TRUE);
877 g_key_file_free(cfile);
882 if(!strncmp(virtstyle, "none", 4)) {
883 s.virtstyle=VIRT_NONE;
884 } else if(!strncmp(virtstyle, "ipliteral", 9)) {
885 s.virtstyle=VIRT_IPLIT;
886 } else if(!strncmp(virtstyle, "iphash", 6)) {
887 s.virtstyle=VIRT_IPHASH;
888 } else if(!strncmp(virtstyle, "cidrhash", 8)) {
889 s.virtstyle=VIRT_CIDR;
890 if(strlen(virtstyle)<10) {
891 g_set_error(e, errdomain, CFILE_VALUE_INVALID, "Invalid value %s for parameter virtstyle in group %s: missing length", virtstyle, groups[i]);
892 g_array_free(retval, TRUE);
893 g_key_file_free(cfile);
896 s.cidrlen=strtol(virtstyle+8, NULL, 0);
898 g_set_error(e, errdomain, CFILE_VALUE_INVALID, "Invalid value %s for parameter virtstyle in group %s", virtstyle, groups[i]);
899 g_array_free(retval, TRUE);
900 g_key_file_free(cfile);
903 if(s.port && !do_oldstyle) {
904 g_warning("A port was specified, but oldstyle exports were not requested. This may not do what you expect.");
905 g_warning("Please read 'man 5 nbd-server' and search for oldstyle for more info");
908 s.virtstyle=VIRT_IPLIT;
910 /* Don't need to free this, it's not our string */
912 /* Don't append values for the [generic] group */
914 s.socket_family = AF_UNSPEC;
915 s.servename = groups[i];
917 append_serve(&s, retval);
924 if(s.flags & F_SDP) {
925 g_set_error(e, errdomain, CFILE_VALUE_UNSUPPORTED, "This nbd-server was built without support for SDP, yet group %s uses it", groups[i]);
926 g_array_free(retval, TRUE);
927 g_key_file_free(cfile);
933 g_set_error(e, errdomain, CFILE_NO_EXPORTS, "The config file does not specify any exports");
935 g_key_file_free(cfile);
940 * Signal handler for SIGCHLD
941 * @param s the signal we're handling (must be SIGCHLD, or something
944 void sigchld_handler(int s) {
949 while((pid=waitpid(-1, &status, WNOHANG)) > 0) {
950 if(WIFEXITED(status)) {
951 msg3(LOG_INFO, "Child exited with %d", WEXITSTATUS(status));
953 i=g_hash_table_lookup(children, &pid);
955 msg3(LOG_INFO, "SIGCHLD received for an unknown child with PID %ld", (long)pid);
957 DEBUG("Removing %d from the list of children", pid);
958 g_hash_table_remove(children, &pid);
964 * Kill a child. Called from sigterm_handler::g_hash_table_foreach.
967 * @param value the value corresponding to the above key
968 * @param user_data a pointer which we always set to 1, so that we know what
971 void killchild(gpointer key, gpointer value, gpointer user_data) {
973 int *parent=user_data;
980 * Handle SIGTERM and dispatch it to our children
981 * @param s the signal we're handling (must be SIGTERM, or something
982 * is severely wrong).
984 void sigterm_handler(int s) {
987 g_hash_table_foreach(children, killchild, &parent);
997 * Detect the size of a file.
999 * @param fhandle An open filedescriptor
1000 * @return the size of the file, or OFFT_MAX if detection was
1003 off_t size_autodetect(int fhandle) {
1006 struct stat stat_buf;
1009 #ifdef HAVE_SYS_MOUNT_H
1010 #ifdef HAVE_SYS_IOCTL_H
1012 DEBUG("looking for export size with ioctl BLKGETSIZE64\n");
1013 if (!ioctl(fhandle, BLKGETSIZE64, &bytes) && bytes) {
1014 return (off_t)bytes;
1016 #endif /* BLKGETSIZE64 */
1017 #endif /* HAVE_SYS_IOCTL_H */
1018 #endif /* HAVE_SYS_MOUNT_H */
1020 DEBUG("looking for fhandle size with fstat\n");
1021 stat_buf.st_size = 0;
1022 error = fstat(fhandle, &stat_buf);
1024 if(stat_buf.st_size > 0)
1025 return (off_t)stat_buf.st_size;
1027 err("fstat failed: %m");
1030 DEBUG("looking for fhandle size with lseek SEEK_END\n");
1031 es = lseek(fhandle, (off_t)0, SEEK_END);
1032 if (es > ((off_t)0)) {
1035 DEBUG("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
1038 err("Could not find size of exported block device: %m");
1043 * Get the file handle and offset, given an export offset.
1045 * @param export An array of export files
1046 * @param a The offset to get corresponding file/offset for
1047 * @param fhandle [out] File descriptor
1048 * @param foffset [out] Offset into fhandle
1049 * @param maxbytes [out] Tells how many bytes can be read/written
1050 * from fhandle starting at foffset (0 if there is no limit)
1051 * @return 0 on success, -1 on failure
1053 int get_filepos(GArray* export, off_t a, int* fhandle, off_t* foffset, size_t* maxbytes ) {
1054 /* Negative offset not allowed */
1058 /* Binary search for last file with starting offset <= a */
1061 int end = export->len - 1;
1062 while( start <= end ) {
1063 int mid = (start + end) / 2;
1064 fi = g_array_index(export, FILE_INFO, mid);
1065 if( fi.startoff < a ) {
1067 } else if( fi.startoff > a ) {
1075 /* end should never go negative, since first startoff is 0 and a >= 0 */
1078 fi = g_array_index(export, FILE_INFO, end);
1079 *fhandle = fi.fhandle;
1080 *foffset = a - fi.startoff;
1082 if( end+1 < export->len ) {
1083 FILE_INFO fi_next = g_array_index(export, FILE_INFO, end+1);
1084 *maxbytes = fi_next.startoff - a;
1091 * seek to a position in a file, with error handling.
1092 * @param handle a filedescriptor
1093 * @param a position to seek to
1094 * @todo get rid of this; lastpoint is a global variable right now, but it
1095 * shouldn't be. If we pass it on as a parameter, that makes things a *lot*
1098 void myseek(int handle,off_t a) {
1099 if (lseek(handle, a, SEEK_SET) < 0) {
1100 err("Can not seek locally!\n");
1105 * Write an amount of bytes at a given offset to the right file. This
1106 * abstracts the write-side of the multiple file option.
1108 * @param a The offset where the write should start
1109 * @param buf The buffer to write from
1110 * @param len The length of buf
1111 * @param client The client we're serving for
1112 * @param fua Flag to indicate 'Force Unit Access'
1113 * @return The number of bytes actually written, or -1 in case of an error
1115 ssize_t rawexpwrite(off_t a, char *buf, size_t len, CLIENT *client, int fua) {
1121 if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
1123 if(maxbytes && len > maxbytes)
1126 DEBUG("(WRITE to fd %d offset %llu len %u fua %d), ", fhandle, (long long unsigned)foffset, (unsigned int)len, fua);
1128 myseek(fhandle, foffset);
1129 retval = write(fhandle, buf, len);
1130 if(client->server->flags & F_SYNC) {
1134 /* This is where we would do the following
1135 * #ifdef USE_SYNC_FILE_RANGE
1136 * However, we don't, for the reasons set out below
1137 * by Christoph Hellwig <hch@infradead.org>
1140 * fdatasync is equivalent to fsync except that it does not flush
1141 * non-essential metadata (basically just timestamps in practice), but it
1142 * does flush metadata requried to find the data again, e.g. allocation
1143 * information and extent maps. sync_file_range does nothing but flush
1144 * out pagecache content - it means you basically won't get your data
1145 * back in case of a crash if you either:
1147 * a) have a volatile write cache in your disk (e.g. any normal SATA disk)
1148 * b) are using a sparse file on a filesystem
1149 * c) are using a fallocate-preallocated file on a filesystem
1150 * d) use any file on a COW filesystem like btrfs
1152 * e.g. it only does anything useful for you if you do not have a volatile
1153 * write cache, and either use a raw block device node, or just overwrite
1154 * an already fully allocated (and not preallocated) file on a non-COW
1158 * What we should do is open a second FD with O_DSYNC set, then write to
1159 * that when appropriate. However, with a Linux client, every REQ_FUA
1160 * immediately follows a REQ_FLUSH, so fdatasync does not cause performance
1165 sync_file_range(fhandle, foffset, len,
1166 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE |
1167 SYNC_FILE_RANGE_WAIT_AFTER);
1176 * Call rawexpwrite repeatedly until all data has been written.
1178 * @param a The offset where the write should start
1179 * @param buf The buffer to write from
1180 * @param len The length of buf
1181 * @param client The client we're serving for
1182 * @param fua Flag to indicate 'Force Unit Access'
1183 * @return 0 on success, nonzero on failure
1185 int rawexpwrite_fully(off_t a, char *buf, size_t len, CLIENT *client, int fua) {
1188 while(len > 0 && (ret=rawexpwrite(a, buf, len, client, fua)) > 0 ) {
1193 return (ret < 0 || len != 0);
1197 * Read an amount of bytes at a given offset from the right file. This
1198 * abstracts the read-side of the multiple files option.
1200 * @param a The offset where the read should start
1201 * @param buf A buffer to read into
1202 * @param len The size of buf
1203 * @param client The client we're serving for
1204 * @return The number of bytes actually read, or -1 in case of an
1207 ssize_t rawexpread(off_t a, char *buf, size_t len, CLIENT *client) {
1212 if(get_filepos(client->export, a, &fhandle, &foffset, &maxbytes))
1214 if(maxbytes && len > maxbytes)
1217 DEBUG("(READ from fd %d offset %llu len %u), ", fhandle, (long long unsigned int)foffset, (unsigned int)len);
1219 myseek(fhandle, foffset);
1220 return read(fhandle, buf, len);
1224 * Call rawexpread repeatedly until all data has been read.
1225 * @return 0 on success, nonzero on failure
1227 int rawexpread_fully(off_t a, char *buf, size_t len, CLIENT *client) {
1230 while(len > 0 && (ret=rawexpread(a, buf, len, client)) > 0 ) {
1235 return (ret < 0 || len != 0);
1239 * Read an amount of bytes at a given offset from the right file. This
1240 * abstracts the read-side of the copyonwrite stuff, and calls
1241 * rawexpread() with the right parameters to do the actual work.
1242 * @param a The offset where the read should start
1243 * @param buf A buffer to read into
1244 * @param len The size of buf
1245 * @param client The client we're going to read for
1246 * @return 0 on success, nonzero on failure
1248 int expread(off_t a, char *buf, size_t len, CLIENT *client) {
1249 off_t rdlen, offset;
1250 off_t mapcnt, mapl, maph, pagestart;
1252 if (!(client->server->flags & F_COPYONWRITE))
1253 return(rawexpread_fully(a, buf, len, client));
1254 DEBUG("Asked to read %u bytes at %llu.\n", (unsigned int)len, (unsigned long long)a);
1256 mapl=a/DIFFPAGESIZE; maph=(a+len-1)/DIFFPAGESIZE;
1258 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
1259 pagestart=mapcnt*DIFFPAGESIZE;
1261 rdlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
1262 len : (size_t)DIFFPAGESIZE-offset;
1263 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
1264 DEBUG("Page %llu is at %lu\n", (unsigned long long)mapcnt,
1265 (unsigned long)(client->difmap[mapcnt]));
1266 myseek(client->difffile, client->difmap[mapcnt]*DIFFPAGESIZE+offset);
1267 if (read(client->difffile, buf, rdlen) != rdlen) return -1;
1268 } else { /* the block is not there */
1269 DEBUG("Page %llu is not here, we read the original one\n",
1270 (unsigned long long)mapcnt);
1271 if(rawexpread_fully(a, buf, rdlen, client)) return -1;
1273 len-=rdlen; a+=rdlen; buf+=rdlen;
1279 * Write an amount of bytes at a given offset to the right file. This
1280 * abstracts the write-side of the copyonwrite option, and calls
1281 * rawexpwrite() with the right parameters to do the actual work.
1283 * @param a The offset where the write should start
1284 * @param buf The buffer to write from
1285 * @param len The length of buf
1286 * @param client The client we're going to write for.
1287 * @param fua Flag to indicate 'Force Unit Access'
1288 * @return 0 on success, nonzero on failure
1290 int expwrite(off_t a, char *buf, size_t len, CLIENT *client, int fua) {
1291 char pagebuf[DIFFPAGESIZE];
1292 off_t mapcnt,mapl,maph;
1297 if (!(client->server->flags & F_COPYONWRITE))
1298 return(rawexpwrite_fully(a, buf, len, client, fua));
1299 DEBUG("Asked to write %u bytes at %llu.\n", (unsigned int)len, (unsigned long long)a);
1301 mapl=a/DIFFPAGESIZE ; maph=(a+len-1)/DIFFPAGESIZE ;
1303 for (mapcnt=mapl;mapcnt<=maph;mapcnt++) {
1304 pagestart=mapcnt*DIFFPAGESIZE ;
1305 offset=a-pagestart ;
1306 wrlen=(0<DIFFPAGESIZE-offset && len<(size_t)(DIFFPAGESIZE-offset)) ?
1307 len : (size_t)DIFFPAGESIZE-offset;
1309 if (client->difmap[mapcnt]!=(u32)(-1)) { /* the block is already there */
1310 DEBUG("Page %llu is at %lu\n", (unsigned long long)mapcnt,
1311 (unsigned long)(client->difmap[mapcnt])) ;
1312 myseek(client->difffile,
1313 client->difmap[mapcnt]*DIFFPAGESIZE+offset);
1314 if (write(client->difffile, buf, wrlen) != wrlen) return -1 ;
1315 } else { /* the block is not there */
1316 myseek(client->difffile,client->difffilelen*DIFFPAGESIZE) ;
1317 client->difmap[mapcnt]=(client->server->flags&F_SPARSE)?mapcnt:client->difffilelen++;
1318 DEBUG("Page %llu is not here, we put it at %lu\n",
1319 (unsigned long long)mapcnt,
1320 (unsigned long)(client->difmap[mapcnt]));
1321 rdlen=DIFFPAGESIZE ;
1322 if (rawexpread_fully(pagestart, pagebuf, rdlen, client))
1324 memcpy(pagebuf+offset,buf,wrlen) ;
1325 if (write(client->difffile, pagebuf, DIFFPAGESIZE) !=
1329 len-=wrlen ; a+=wrlen ; buf+=wrlen ;
1331 if (client->server->flags & F_SYNC) {
1332 fsync(client->difffile);
1334 /* open question: would it be cheaper to do multiple sync_file_ranges?
1335 as we iterate through the above?
1337 fdatasync(client->difffile);
1343 * Flush data to a client
1345 * @param client The client we're going to write for.
1346 * @return 0 on success, nonzero on failure
1348 int expflush(CLIENT *client) {
1351 if (client->server->flags & F_COPYONWRITE) {
1352 return fsync(client->difffile);
1355 for (i = 0; i < client->export->len; i++) {
1356 FILE_INFO fi = g_array_index(client->export, FILE_INFO, i);
1357 if (fsync(fi.fhandle) < 0)
1365 * Do the initial negotiation.
1367 * @param client The client we're negotiating with.
1369 CLIENT* negotiate(int net, CLIENT *client, GArray* servers, int phase) {
1372 uint32_t flags = NBD_FLAG_HAS_FLAGS;
1373 uint16_t smallflags = 0;
1376 memset(zeros, '\0', sizeof(zeros));
1377 if(phase & NEG_INIT) {
1379 if (write(net, INIT_PASSWD, 8) < 0) {
1380 err_nonfatal("Negotiation failed: %m");
1384 if(phase & NEG_MODERN) {
1386 magic = htonll(opts_magic);
1389 magic = htonll(cliserv_magic);
1391 if (write(net, &magic, sizeof(magic)) < 0) {
1392 err_nonfatal("Negotiation failed: %m");
1397 if(phase & NEG_MODERN) {
1406 err("programmer error");
1407 if (write(net, &smallflags, sizeof(uint16_t)) < 0)
1408 err("Negotiation failed: %m");
1409 if (read(net, &reserved, sizeof(reserved)) < 0)
1410 err("Negotiation failed: %m");
1411 if (read(net, &magic, sizeof(magic)) < 0)
1412 err("Negotiation failed: %m");
1413 magic = ntohll(magic);
1414 if(magic != opts_magic) {
1418 if (read(net, &opt, sizeof(opt)) < 0)
1419 err("Negotiation failed: %m");
1421 if(opt != NBD_OPT_EXPORT_NAME) {
1425 if (read(net, &namelen, sizeof(namelen)) < 0)
1426 err("Negotiation failed: %m");
1427 namelen = ntohl(namelen);
1428 name = malloc(namelen+1);
1430 if (read(net, name, namelen) < 0)
1431 err("Negotiation failed: %m");
1432 for(i=0; i<servers->len; i++) {
1433 SERVER* serve = &(g_array_index(servers, SERVER, i));
1434 if(!strcmp(serve->servename, name)) {
1435 CLIENT* client = g_new0(CLIENT, 1);
1436 client->server = serve;
1437 client->exportsize = OFFT_MAX;
1439 client->modern = TRUE;
1440 client->transactionlogfd = -1;
1449 size_host = htonll((u64)(client->exportsize));
1450 if (write(net, &size_host, 8) < 0)
1451 err("Negotiation failed: %m");
1452 if (client->server->flags & F_READONLY)
1453 flags |= NBD_FLAG_READ_ONLY;
1454 if (client->server->flags & F_FLUSH)
1455 flags |= NBD_FLAG_SEND_FLUSH;
1456 if (client->server->flags & F_FUA)
1457 flags |= NBD_FLAG_SEND_FUA;
1458 if (client->server->flags & F_ROTATIONAL)
1459 flags |= NBD_FLAG_ROTATIONAL;
1460 if (phase & NEG_OLD) {
1462 flags = htonl(flags);
1463 if (write(client->net, &flags, 4) < 0)
1464 err("Negotiation failed: %m");
1467 smallflags = (uint16_t)(flags & ~((uint16_t)0));
1468 smallflags = htons(smallflags);
1469 if (write(client->net, &smallflags, sizeof(smallflags)) < 0) {
1470 err("Negotiation failed: %m");
1474 if (write(client->net, zeros, 124) < 0)
1475 err("Negotiation failed: %m");
1479 /** sending macro. */
1480 #define SEND(net,reply) { writeit( net, &reply, sizeof( reply )); \
1481 if (client->transactionlogfd != -1) \
1482 writeit(client->transactionlogfd, &reply, sizeof(reply)); }
1484 #define ERROR(client,reply,errcode) { reply.error = htonl(errcode); SEND(client->net,reply); reply.error = 0; }
1486 * Serve a file to a single client.
1488 * @todo This beast needs to be split up in many tiny little manageable
1489 * pieces. Preferably with a chainsaw.
1491 * @param client The client we're going to serve to.
1492 * @return when the client disconnects
1494 int mainloop(CLIENT *client) {
1495 struct nbd_request request;
1496 struct nbd_reply reply;
1497 gboolean go_on=TRUE;
1501 negotiate(client->net, client, NULL, client->modern ? NEG_MODERN : (NEG_OLD | NEG_INIT));
1502 DEBUG("Entering request loop!\n");
1503 reply.magic = htonl(NBD_REPLY_MAGIC);
1516 readit(client->net, &request, sizeof(request));
1517 if (client->transactionlogfd != -1)
1518 writeit(client->transactionlogfd, &request, sizeof(request));
1520 request.from = ntohll(request.from);
1521 request.type = ntohl(request.type);
1522 command = request.type & NBD_CMD_MASK_COMMAND;
1523 len = ntohl(request.len);
1525 DEBUG("%s from %llu (%llu) len %d, ", getcommandname(command),
1526 (unsigned long long)request.from,
1527 (unsigned long long)request.from / 512, (unsigned int)len);
1529 if (request.magic != htonl(NBD_REQUEST_MAGIC))
1530 err("Not enough magic.");
1532 memcpy(reply.handle, request.handle, sizeof(reply.handle));
1534 if ((command==NBD_CMD_WRITE) || (command==NBD_CMD_READ)) {
1535 if ((request.from + len) > (OFFT_MAX)) {
1536 DEBUG("[Number too large!]");
1537 ERROR(client, reply, EINVAL);
1541 if (((ssize_t)((off_t)request.from + len) > client->exportsize)) {
1543 ERROR(client, reply, EINVAL);
1548 if (currlen > BUFSIZE - sizeof(struct nbd_reply)) {
1549 currlen = BUFSIZE - sizeof(struct nbd_reply);
1550 msg2(LOG_INFO, "oversized request (this is not a problem)");
1557 msg2(LOG_INFO, "Disconnect request received.");
1558 if (client->server->flags & F_COPYONWRITE) {
1559 if (client->difmap) g_free(client->difmap) ;
1560 close(client->difffile);
1561 unlink(client->difffilename);
1562 free(client->difffilename);
1568 DEBUG("wr: net->buf, ");
1570 readit(client->net, buf, currlen);
1571 DEBUG("buf->exp, ");
1572 if ((client->server->flags & F_READONLY) ||
1573 (client->server->flags & F_AUTOREADONLY)) {
1574 DEBUG("[WRITE to READONLY!]");
1575 ERROR(client, reply, EPERM);
1576 consume(client->net, buf, len-currlen, BUFSIZE);
1579 if (expwrite(request.from, buf, currlen, client,
1580 request.type & NBD_CMD_FLAG_FUA)) {
1581 DEBUG("Write failed: %m" );
1582 ERROR(client, reply, errno);
1583 consume(client->net, buf, len-currlen, BUFSIZE);
1587 request.from += currlen;
1588 currlen = (len < BUFSIZE) ? len : BUFSIZE;
1590 SEND(client->net, reply);
1596 if (expflush(client)) {
1597 DEBUG("Flush failed: %m");
1598 ERROR(client, reply, errno);
1601 SEND(client->net, reply);
1606 DEBUG("exp->buf, ");
1607 memcpy(buf, &reply, sizeof(struct nbd_reply));
1608 if (client->transactionlogfd != -1)
1609 writeit(client->transactionlogfd, &reply, sizeof(reply));
1610 p = buf + sizeof(struct nbd_reply);
1611 writelen = currlen + sizeof(struct nbd_reply);
1613 if (expread(request.from, p, currlen, client)) {
1614 DEBUG("Read failed: %m");
1615 ERROR(client, reply, errno);
1619 DEBUG("buf->net, ");
1620 writeit(client->net, buf, writelen);
1622 request.from += currlen;
1623 currlen = (len < BUFSIZE) ? len : BUFSIZE;
1631 DEBUG ("Ignoring unknown command\n");
1639 * Set up client export array, which is an array of FILE_INFO.
1640 * Also, split a single exportfile into multiple ones, if that was asked.
1641 * @param client information on the client which we want to setup export for
1643 void setupexport(CLIENT* client) {
1645 off_t laststartoff = 0, lastsize = 0;
1646 int multifile = (client->server->flags & F_MULTIFILE);
1648 client->export = g_array_new(TRUE, TRUE, sizeof(FILE_INFO));
1650 /* If multi-file, open as many files as we can.
1651 * If not, open exactly one file.
1652 * Calculate file sizes as we go to get total size. */
1656 gchar* error_string;
1657 mode_t mode = (client->server->flags & F_READONLY) ? O_RDONLY : O_RDWR;
1660 tmpname=g_strdup_printf("%s.%d", client->exportname, i);
1662 tmpname=g_strdup(client->exportname);
1664 DEBUG( "Opening %s\n", tmpname );
1665 fi.fhandle = open(tmpname, mode);
1666 if(fi.fhandle == -1 && mode == O_RDWR) {
1667 /* Try again because maybe media was read-only */
1668 fi.fhandle = open(tmpname, O_RDONLY);
1669 if(fi.fhandle != -1) {
1670 /* Opening the base file in copyonwrite mode is
1672 if(!(client->server->flags & F_COPYONWRITE)) {
1673 client->server->flags |= F_AUTOREADONLY;
1674 client->server->flags |= F_READONLY;
1678 if(fi.fhandle == -1) {
1679 if(multifile && i>0)
1681 error_string=g_strdup_printf(
1682 "Could not open exported file %s: %%m",
1686 fi.startoff = laststartoff + lastsize;
1687 g_array_append_val(client->export, fi);
1690 /* Starting offset and size of this file will be used to
1691 * calculate starting offset of next file */
1692 laststartoff = fi.startoff;
1693 lastsize = size_autodetect(fi.fhandle);
1699 /* Set export size to total calculated size */
1700 client->exportsize = laststartoff + lastsize;
1702 /* Export size may be overridden */
1703 if(client->server->expected_size) {
1704 /* desired size must be <= total calculated size */
1705 if(client->server->expected_size > client->exportsize) {
1706 err("Size of exported file is too big\n");
1709 client->exportsize = client->server->expected_size;
1712 msg3(LOG_INFO, "Size of exported file/device is %llu", (unsigned long long)client->exportsize);
1714 msg3(LOG_INFO, "Total number of files: %d", i);
1718 int copyonwrite_prepare(CLIENT* client) {
1720 if ((client->difffilename = malloc(1024))==NULL)
1721 err("Failed to allocate string for diff file name");
1722 snprintf(client->difffilename, 1024, "%s-%s-%d.diff",client->exportname,client->clientname,
1724 client->difffilename[1023]='\0';
1725 msg3(LOG_INFO,"About to create map and diff file %s",client->difffilename) ;
1726 client->difffile=open(client->difffilename,O_RDWR | O_CREAT | O_TRUNC,0600) ;
1727 if (client->difffile<0) err("Could not create diff file (%m)") ;
1728 if ((client->difmap=calloc(client->exportsize/DIFFPAGESIZE,sizeof(u32)))==NULL)
1729 err("Could not allocate memory") ;
1730 for (i=0;i<client->exportsize/DIFFPAGESIZE;i++) client->difmap[i]=(u32)-1 ;
1736 * Run a command. This is used for the ``prerun'' and ``postrun'' config file
1739 * @param command the command to be ran. Read from the config file
1740 * @param file the file name we're about to export
1742 int do_run(gchar* command, gchar* file) {
1746 if(command && *command) {
1747 cmd = g_strdup_printf(command, file);
1755 * Serve a connection.
1757 * @todo allow for multithreading, perhaps use libevent. Not just yet, though;
1758 * follow the road map.
1760 * @param client a connected client
1762 void serveconnection(CLIENT *client) {
1763 if (client->server->transactionlog && (client->transactionlogfd == -1))
1765 if (-1 == (client->transactionlogfd = open(client->server->transactionlog,
1767 S_IRUSR | S_IWUSR)))
1768 g_warning("Could not open transaction log %s",
1769 client->server->transactionlog);
1772 if(do_run(client->server->prerun, client->exportname)) {
1775 setupexport(client);
1777 if (client->server->flags & F_COPYONWRITE) {
1778 copyonwrite_prepare(client);
1781 setmysockopt(client->net);
1784 do_run(client->server->postrun, client->exportname);
1786 if (-1 != client->transactionlogfd)
1788 close(client->transactionlogfd);
1789 client->transactionlogfd = -1;
1794 * Find the name of the file we have to serve. This will use g_strdup_printf
1795 * to put the IP address of the client inside a filename containing
1796 * "%s" (in the form as specified by the "virtstyle" option). That name
1797 * is then written to client->exportname.
1799 * @param net A socket connected to an nbd client
1800 * @param client information about the client. The IP address in human-readable
1801 * format will be written to a new char* buffer, the address of which will be
1802 * stored in client->clientname.
1804 void set_peername(int net, CLIENT *client) {
1805 struct sockaddr_storage addrin;
1806 struct sockaddr_storage netaddr;
1807 struct sockaddr_in *netaddr4 = NULL;
1808 struct sockaddr_in6 *netaddr6 = NULL;
1809 size_t addrinlen = sizeof( addrin );
1810 struct addrinfo hints;
1811 struct addrinfo *ai = NULL;
1812 char peername[NI_MAXHOST];
1813 char netname[NI_MAXHOST];
1819 if (getpeername(net, (struct sockaddr *) &addrin, (socklen_t *)&addrinlen) < 0)
1820 err("getsockname failed: %m");
1822 getnameinfo((struct sockaddr *)&addrin, (socklen_t)addrinlen,
1823 peername, sizeof (peername), NULL, 0, NI_NUMERICHOST);
1825 memset(&hints, '\0', sizeof (hints));
1826 hints.ai_flags = AI_ADDRCONFIG;
1827 e = getaddrinfo(peername, NULL, &hints, &ai);
1830 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
1835 switch(client->server->virtstyle) {
1837 client->exportname=g_strdup(client->server->exportname);
1840 for(i=0;i<strlen(peername);i++) {
1841 if(peername[i]=='.') {
1846 client->exportname=g_strdup_printf(client->server->exportname, peername);
1849 memcpy(&netaddr, &addrin, addrinlen);
1850 if(ai->ai_family == AF_INET) {
1851 netaddr4 = (struct sockaddr_in *)&netaddr;
1852 (netaddr4->sin_addr).s_addr>>=32-(client->server->cidrlen);
1853 (netaddr4->sin_addr).s_addr<<=32-(client->server->cidrlen);
1855 getnameinfo((struct sockaddr *) netaddr4, (socklen_t) addrinlen,
1856 netname, sizeof (netname), NULL, 0, NI_NUMERICHOST);
1857 tmp=g_strdup_printf("%s/%s", netname, peername);
1858 }else if(ai->ai_family == AF_INET6) {
1859 netaddr6 = (struct sockaddr_in6 *)&netaddr;
1861 shift = 128-(client->server->cidrlen);
1863 while(shift >= 32) {
1864 ((netaddr6->sin6_addr).s6_addr32[i])=0;
1868 (netaddr6->sin6_addr).s6_addr32[i]>>=shift;
1869 (netaddr6->sin6_addr).s6_addr32[i]<<=shift;
1871 getnameinfo((struct sockaddr *)netaddr6, (socklen_t)addrinlen,
1872 netname, sizeof(netname), NULL, 0, NI_NUMERICHOST);
1873 tmp=g_strdup_printf("%s/%s", netname, peername);
1877 client->exportname=g_strdup_printf(client->server->exportname, tmp);
1883 msg4(LOG_INFO, "connect from %s, assigned file is %s",
1884 peername, client->exportname);
1885 client->clientname=g_strdup(peername);
1890 * @param data a pointer to pid_t which should be freed
1892 void destroy_pid_t(gpointer data) {
1897 * Loop through the available servers, and serve them. Never returns.
1899 int serveloop(GArray* servers) {
1900 struct sockaddr_storage addrin;
1901 socklen_t addrinlen=sizeof(addrin);
1909 * Set up the master fd_set. The set of descriptors we need
1910 * to select() for never changes anyway and it buys us a *lot*
1911 * of time to only build this once. However, if we ever choose
1912 * to not fork() for clients anymore, we may have to revisit
1917 for(i=0;i<servers->len;i++) {
1918 if((sock=(g_array_index(servers, SERVER, i)).socket)) {
1919 FD_SET(sock, &mset);
1920 max=sock>max?sock:max;
1924 FD_SET(modernsock, &mset);
1925 max=modernsock>max?modernsock:max;
1928 CLIENT *client = NULL;
1931 memcpy(&rset, &mset, sizeof(fd_set));
1932 if(select(max+1, &rset, NULL, NULL, NULL)>0) {
1937 if(FD_ISSET(modernsock, &rset)) {
1938 if((net=accept(modernsock, (struct sockaddr *) &addrin, &addrinlen)) < 0)
1940 client = negotiate(net, NULL, servers, NEG_INIT | NEG_MODERN);
1942 err_nonfatal("negotiation failed");
1947 serve = client->server;
1949 for(i=0;i<servers->len && !net;i++) {
1950 serve=&(g_array_index(servers, SERVER, i));
1951 if(FD_ISSET(serve->socket, &rset)) {
1952 if ((net=accept(serve->socket, (struct sockaddr *) &addrin, &addrinlen)) < 0)
1959 if(serve->max_connections > 0 &&
1960 g_hash_table_size(children) >= serve->max_connections) {
1961 msg2(LOG_INFO, "Max connections reached");
1965 if((sock_flags = fcntl(net, F_GETFL, 0))==-1) {
1966 err("fcntl F_GETFL");
1968 if(fcntl(net, F_SETFL, sock_flags &~O_NONBLOCK)==-1) {
1969 err("fcntl F_SETFL ~O_NONBLOCK");
1972 client = g_new0(CLIENT, 1);
1973 client->server=serve;
1974 client->exportsize=OFFT_MAX;
1976 client->transactionlogfd = -1;
1978 set_peername(net, client);
1979 if (!authorized_client(client)) {
1980 msg2(LOG_INFO,"Unauthorized client") ;
1984 msg2(LOG_INFO,"Authorized client") ;
1985 pid=g_malloc(sizeof(pid_t));
1988 if ((*pid=fork())<0) {
1989 msg3(LOG_INFO,"Could not fork (%s)",strerror(errno)) ;
1993 if (*pid>0) { /* parent */
1995 g_hash_table_insert(children, pid, pid);
1999 g_hash_table_destroy(children);
2000 for(i=0;i<servers->len;i++) {
2001 serve=&g_array_index(servers, SERVER, i);
2002 close(serve->socket);
2004 /* FALSE does not free the
2005 actual data. This is required,
2006 because the client has a
2007 direct reference into that
2008 data, and otherwise we get a
2010 g_array_free(servers, FALSE);
2013 msg2(LOG_INFO,"Starting to serve");
2014 serveconnection(client);
2021 void dosockopts(int socket) {
2029 /* lose the pesky "Address already in use" error message */
2030 if (setsockopt(socket,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) {
2031 err("setsockopt SO_REUSEADDR");
2033 if (setsockopt(socket,SOL_SOCKET,SO_KEEPALIVE,&yes,sizeof(int)) == -1) {
2034 err("setsockopt SO_KEEPALIVE");
2037 /* make the listening socket non-blocking */
2038 if ((sock_flags = fcntl(socket, F_GETFL, 0)) == -1) {
2039 err("fcntl F_GETFL");
2041 if (fcntl(socket, F_SETFL, sock_flags | O_NONBLOCK) == -1) {
2042 err("fcntl F_SETFL O_NONBLOCK");
2047 * Connect a server's socket.
2049 * @param serve the server we want to connect.
2051 int setup_serve(SERVER *serve) {
2052 struct addrinfo hints;
2053 struct addrinfo *ai = NULL;
2058 return serve->servename ? 1 : 0;
2060 memset(&hints,'\0',sizeof(hints));
2061 hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG | AI_NUMERICSERV;
2062 hints.ai_socktype = SOCK_STREAM;
2063 hints.ai_family = serve->socket_family;
2065 port = g_strdup_printf ("%d", serve->port);
2069 e = getaddrinfo(serve->listenaddr,port,&hints,&ai);
2074 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
2080 if(serve->socket_family == AF_UNSPEC)
2081 serve->socket_family = ai->ai_family;
2084 if ((serve->flags) && F_SDP) {
2085 if (ai->ai_family == AF_INET)
2086 ai->ai_family = AF_INET_SDP;
2087 else (ai->ai_family == AF_INET6)
2088 ai->ai_family = AF_INET6_SDP;
2091 if ((serve->socket = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol)) < 0)
2094 dosockopts(serve->socket);
2096 DEBUG("Waiting for connections... bind, ");
2097 e = bind(serve->socket, ai->ai_addr, ai->ai_addrlen);
2098 if (e != 0 && errno != EADDRINUSE)
2101 if (listen(serve->socket, 1) < 0)
2105 if(serve->servename) {
2112 void open_modern(void) {
2113 struct addrinfo hints;
2114 struct addrinfo* ai = NULL;
2118 memset(&hints, '\0', sizeof(hints));
2119 hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
2120 hints.ai_socktype = SOCK_STREAM;
2121 hints.ai_family = AF_UNSPEC;
2122 hints.ai_protocol = IPPROTO_TCP;
2123 e = getaddrinfo(modern_listen, modernport, &hints, &ai);
2125 fprintf(stderr, "getaddrinfo failed: %s\n", gai_strerror(e));
2128 if((modernsock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol))<0) {
2132 dosockopts(modernsock);
2134 if(bind(modernsock, ai->ai_addr, ai->ai_addrlen)) {
2137 if(listen(modernsock, 10) <0) {
2145 * Connect our servers.
2147 void setup_servers(GArray* servers) {
2149 struct sigaction sa;
2152 for(i=0;i<servers->len;i++) {
2153 want_modern |= setup_serve(&(g_array_index(servers, SERVER, i)));
2158 children=g_hash_table_new_full(g_int_hash, g_int_equal, NULL, destroy_pid_t);
2160 sa.sa_handler = sigchld_handler;
2161 sigemptyset(&sa.sa_mask);
2162 sa.sa_flags = SA_RESTART;
2163 if(sigaction(SIGCHLD, &sa, NULL) == -1)
2164 err("sigaction: %m");
2165 sa.sa_handler = sigterm_handler;
2166 sigemptyset(&sa.sa_mask);
2167 sa.sa_flags = SA_RESTART;
2168 if(sigaction(SIGTERM, &sa, NULL) == -1)
2169 err("sigaction: %m");
2173 * Go daemon (unless we specified at compile time that we didn't want this)
2174 * @param serve the first server of our configuration. If its port is zero,
2175 * then do not daemonize, because we're doing inetd then. This parameter
2176 * is only used to create a PID file of the form
2177 * /var/run/nbd-server.<port>.pid; it's not modified in any way.
2179 #if !defined(NODAEMON)
2180 void daemonize(SERVER* serve) {
2183 if(serve && !(serve->port)) {
2189 if(!*pidftemplate) {
2191 strncpy(pidftemplate, "/var/run/nbd-server.%d.pid", 255);
2193 strncpy(pidftemplate, "/var/run/nbd-server.pid", 255);
2196 snprintf(pidfname, 255, pidftemplate, serve ? serve->port : 0);
2197 pidf=fopen(pidfname, "w");
2199 fprintf(pidf,"%d\n", (int)getpid());
2203 fprintf(stderr, "Not fatal; continuing");
2207 #define daemonize(serve)
2208 #endif /* !defined(NODAEMON) */
2211 * Everything beyond this point (in the file) is run in non-daemon mode.
2212 * The stuff above daemonize() isn't.
2215 void serve_err(SERVER* serve, const char* msg) G_GNUC_NORETURN;
2217 void serve_err(SERVER* serve, const char* msg) {
2218 g_message("Export of %s on port %d failed:", serve->exportname,
2224 * Set up user-ID and/or group-ID
2226 void dousers(void) {
2231 gr=getgrnam(rungroup);
2233 str = g_strdup_printf("Invalid group name: %s", rungroup);
2236 if(setgid(gr->gr_gid)<0) {
2237 err("Could not set GID: %m");
2241 pw=getpwnam(runuser);
2243 str = g_strdup_printf("Invalid user name: %s", runuser);
2246 if(setuid(pw->pw_uid)<0) {
2247 err("Could not set UID: %m");
2253 void glib_message_syslog_redirect(const gchar *log_domain,
2254 GLogLevelFlags log_level,
2255 const gchar *message,
2258 int level=LOG_DEBUG;
2262 case G_LOG_FLAG_FATAL:
2263 case G_LOG_LEVEL_CRITICAL:
2264 case G_LOG_LEVEL_ERROR:
2267 case G_LOG_LEVEL_WARNING:
2270 case G_LOG_LEVEL_MESSAGE:
2271 case G_LOG_LEVEL_INFO:
2274 case G_LOG_LEVEL_DEBUG:
2279 syslog(level, "%s", message);
2284 * Main entry point...
2286 int main(int argc, char *argv[]) {
2291 if (sizeof( struct nbd_request )!=28) {
2292 fprintf(stderr,"Bad size of structure. Alignment problems?\n");
2293 exit(EXIT_FAILURE) ;
2296 memset(pidftemplate, '\0', 256);
2299 config_file_pos = g_strdup(CFILE);
2300 serve=cmdline(argc, argv);
2301 servers = parse_cfile(config_file_pos, &err);
2304 serve->socket_family = AF_UNSPEC;
2306 append_serve(serve, servers);
2308 if (!(serve->port)) {
2311 /* You really should define ISSERVER if you're going to use
2312 * inetd mode, but if you don't, closing stdout and stderr
2313 * (which inetd had connected to the client socket) will let it
2317 open("/dev/null", O_WRONLY);
2318 open("/dev/null", O_WRONLY);
2319 g_log_set_default_handler( glib_message_syslog_redirect, NULL );
2321 client=g_malloc(sizeof(CLIENT));
2322 client->server=serve;
2324 client->exportsize=OFFT_MAX;
2325 set_peername(0,client);
2326 serveconnection(client);
2331 if(!servers || !servers->len) {
2332 if(err && !(err->domain == g_quark_from_string("parse_cfile")
2333 && err->code == CFILE_NOTFOUND)) {
2334 g_warning("Could not parse config file: %s",
2335 err ? err->message : "Unknown error");
2339 g_warning("Specifying an export on the command line is deprecated.");
2340 g_warning("Please use a configuration file instead.");
2343 if((!serve) && (!servers||!servers->len)) {
2344 g_message("No configured exports; quitting.");
2349 setup_servers(servers);